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Summary of the impact

Full-waveform inversion (FWI) is a seismic technique for exploring the
interior of the Earth; it has been developed at Imperial College over two
decades, from a promising concept into a fully commercialised industrial
process that has been widely adopted across the petroleum industry. The
technique improves both the spatial resolution and the fidelity with which
the sub-surface can be imaged in three dimensions. All the major
multinational petroleum companies now use FWI internally, and all the
major oil-field service companies offer the technology to the wider
industry. Since its first commercial uptake in 2008, its application has
influenced at least one hundred drilling decisions worldwide, and as a
consequence it has generated additional value of at least $500M within the
petroleum industry.

Underpinning research

Unlike conventional travel-time tomography, full-waveform inversion is a
tomographic scheme that fully honours the physics of finite-frequency wave
propagation; it is principally this feature that improves its resolution
and its accuracy. The fundamentals of the method have long been
understood; the intellectual challenge has been to render this theory
computationally tractable and to apply it successfully to imperfect data
using realisable computer hardware configurations. In the mid 1990's,
Gerhard Pratt (Elf Lecturer, Imperial College, 1993-1998) and co-workers
at Imperial College developed the first practical implementation of
acoustic isotropic FWI in two-dimensions [1]. They developed an algorithm
in the frequency domain that was orders of magnitude faster than hitherto,
and demonstrated that this could successfully invert both synthetic and
field seismic datasets in 2D [2].

A decade later, Professors Michael Warner (Imperial, 1993-2013), Joanna
Morgan (Imperial, 1998-2013), Yanghua Wang (Imperial, 2003-2013) and their
co-workers built upon these early successes to extend the method into
three-dimensions, first in the frequency domain, and then into the
more-effective time domain, successively incorporating attenuation,
anisotropy and elastic effects. Although the extension from two to three
dimensions is conceptually simple, its practical computational
implementation is not. The direct solution of the wave equation that
Gerhard Pratt used in 2D is not computationally feasible in 3D. Instead,
the group developed iterative 3D solvers in the frequency domain, and
later, massively-parallel solvers in the time domain. Since the real world
is three dimensional and anisotropic, these developments were fundamental
to being able to apply the methodology usefully to real industrial
problems.

Michael Warner and his co-authors Ivan Stekl and Adrian Umpleby, also
from Imperial, obtained the first FWI results from 3D field data in 2008
[3], for which they were awarded the Bonarelli prize by the EAGE, the
leading European professional organisation in petroleum geoscience. Since
then, the range of problems, targets and datasets to which the methodology
can be successfully applied has continued to grow [4, 5, 6]. The first 3D
anisotropic results from field data were obtained in 2010, and the first
elastic results appeared in 2012.

* [3] M. Warner, I. Stekl, A. Umpleby, "Efficient and effective 3D
wavefield tomography", Paper presented at the 70th European Association of
Geoscientists and Engineers Annual Conference, Rome, (2008). http://www.earthdoc.org/publication/publicationdetails/?publication=9831(This presentation demonstrated the first ever successful application
of 3D FWI to field data. The paper was awarded the Bonarelli prize by
the European Association of Geoscientists & Engineers (EAGE). Within
a year of this paper, the method was being applied commercially by BP
and others.)

* [5] M. Warner, A. Ratcliffe, T. Nangoo, et al., "Anisotropic 3D
full-waveform inversion", Geophysics, Vol 78, pp. R59-R80, (2013) DOI:
10.1190/GEO2012-0338.1(This joint Imperial/industry paper is the first that describes how 3D
FWI can be applied to invert anisotropic field data. The work was
completed in 2010; full publication was embargoed by the industrial
sponsors until 2013.)

[6] Members of the FWI research team appear as inventors on nine patents
related to FWI: GB 1101345.5, GB 1121934.2, GB 1121932.6, GB 1206073.7, GB
1219828.9., US 2012/028470, US 2012/028504, US 2012/039057, US
2012/039077, and have held over thirty grants supporting the development
and application of FWI with a total value of over £6M from three research
councils, seventeen commercial partners, two government departments and
two charities.

Details of the impact

Research at Imperial into full-waveform inversion has had two distinct
impacts on the petroleum industry: one specific, where individual
companies are directly using software developed at Imperial College to
apply 3D FWI to their own and their clients' seismic data, and one
generic, ranging broadly across the industrial sector, where the uptake
and effectiveness of FWI has been increased by the direct research
contribution made by Imperial. In both cases, the application of FWI to
seismic data has affected individual drilling and investment decisions
across the petroleum industry worldwide, changing drilling priorities,
borehole locations, sub-surface risk assessment and mitigation, and
ultimately influencing which plays are drilled and which are not, adding
consequent value to individual petroleum assets.

Generic across the petroleum sector

The petroleum industry worldwide has adopted 3D full-waveform seismic
inversion as a new tool with which to improve the quality of images and
interpretations of the subsurface for petroleum exploration and
production. A decade ago, there was no capability to undertake 3D FWI of
any description within the petroleum sector. Today, every large
multinational petroleum company (BP, Chevron, ConocoPhillips, ExxonMobil,
Shell, TOTAL), and many mid-sized (BG Group, DONG, ENI, Hess, Maersk,
Nexen, Statoil, Tullow Oil, Woodside) and national oil companies (CNOOC,
Petrobras, Saudi Aramco, Sinopec, among others), have adopted 3D FWI as
part of their technical portfolio for finding and exploiting petroleum
reserves. All the largest oil-field seismic service companies (CGG, ION,
PGS, TGS, WesternGeco) now offer FWI as a commercial service to their
oil-company clients.

Without the specific FWI research contribution made by Imperial over the
past twenty years, and especially without its dissemination, validation
and demonstration on key problems and datasets, the adoption of this
technology would not have begun so early, and its uptake would not have
developed so rapidly, so widely or so successfully.

The head of FWI research at BP and now with TOTAL [7], writes:

"I have been working on the topic of Full waverform inversion for
about 15 years with both BP and Total. My research, and its direct
application to industry problems, was made possible thanks to the
technology for FWI that Gerhard Pratt conceived and developed during his
time at Imperial College: which includes key publications and more
practically, a 2D frequency domain FWI software that pioneered the way
that the industry currently performs FWI. To this date, Gerhard's work
remains the reference in the field and his outstanding contribution to
the community has been recognized by the EAGE Conrad Schlumberger award".

The head of FWI development at Chevron [8], writes:

"In 2007, FWI was an untried, unproven, and potentially unaffordable
technique in 3D. The paper presented at EAGE in Rome, by Warner et al in
2008, demonstrated to a sceptical industry audience that 3D FWI could be
made to work efficiently and effectively on real 3D seismic data. This
success convinced several companies of the value of FWI, and within a
year BP was able to demonstrate the full commercial value of the
technique when applied to a large field dataset. This provided a huge
impetus to others to follow this early lead, and today everyone has the
technology. Without this paper, and the research at Imperial that
underpinned it, 3D FWI would still have happened eventually, but not so
quickly, and perhaps not yet."

Between 2008 and 2012 the industry was estimated, in a public statement
made by WesternGeco at the 2012 SEG conference in Las Vegas, to have spent
more than $200M on seismic data acquisition, data processing, bespoke
computer hardware, software development, and novel acquisition platforms,
specifically to support 3D FWI [9].

During the same period, in a public statement made on 9 June 2013 during
the "Robust FWI Workshop" at the 75th EAGE Conference &
Exhibition in London, BP estimated that additional value of at least $500M
had been generated for the petroleum industry through the application of
FWI to specific seismic datasets that have influenced at least one hundred
individual drilling decisions [9]. This value is realised because improved
imaging leads to improved interpretation, reduced sub-surface risk and HSE
exposure, more discoveries, and more-effective oil and gas development and
extraction.

Around a third of all the 3D seismic data worldwide, to which FWI has
been applied, was estimated in a public statement made by CGG during the
"Advances in Model Building, Imaging, and FWI Workshop" at the 2013 SEG
conference in Houston, to have been analysed using software derived from
that written at Imperial [9].

The head of global technology at Hess [10], writes:

"By 2010, a few successful 3-D Full Waveform Inversion (FWI) results
had been published on modern seismic surveys. Hess conducted a worldwide
review of academic consortia, and discovered that Imperial College was
the only group to have FWI results on a real 3-D seismic data set. The
Imperial College Fullwave consortium was, and still is, the leading
academic group in 3-D full waveform inversion. Hess joined the
consortium in the fall of 2010 to collaborate and learn about ways to
apply FWI to real-world problems. With the assistance of Mike Warner and
his staff, we immediately and successfully applied their
industrial-grade code to one of our major assets, leapfrogging many
companies who were trying to climb the FWI learning curve by
themselves."

The head of geophysics for BG-Group [11], writes:

"BG Group have supported the work at Imperial in 3D FWI since its
initiation in 2006. The team at Imperial are world leading, and the
results of their research and their software are now being used, both
within BG and by our sub-contractors, to assist our exploration and
production worldwide. We are also involved with Mike Warner's group in a
new initiative within Brazil in commencing in 2013, which involves a
>$20m investment from BG Group, and participation from the Federal
University of Rio Grande Norte in Brazil and the University of British
Columbia. As part of this large ongoing project, there is an advanced
plan to purchase the largest high-performance computer in South America
specifically to run the FWI software that Mike Warner's research team
have developed."

Among the companies that have licensed the software, CGG is an oil-field
service company with the largest share of the seismic services market.
They offer extensive FWI services from seven centres worldwide based in
London, Massy, Oslo, Houston, Rio de Janeiro, Singapore and Perth. Their
FWI services are built around the software package developed at Imperial
[9]. Since 2010, they have customised and integrated this package into
their core processing and imaging software, and Imperial and CGG have
jointly published the results of applying this software to industry
seismic data [5]. As a result of adopting Imperial's software, CGG has
moved in three years, from a position where they did not offer FWI as a
commercial service, to become the market leader in this field worldwide
[9]. In order to ensure the continued development and availability of FWI
as a valuable industrial tool and maintain a clear pathway to impact the
spin — out company Sub — Salt Solutions is in the process of being
developed.

Sources to corroborate the impact

[7] Former Head of FWI research at BP, now with Total to confirm use of
the full waveform in BP and Total

[8] Head of FWI Development, Senior Staff Geophysicist with Chevron to
confirm the industrial use of 3D FWI and its link to Imperial College
research

[9] The Industry Technology Facilitator (ITF) act as brokers between
research providers and the international petroleum industry. Their lead
facilitator for exploration and production is able to provide
corroboration of unpublished public statements made by the petroleum
industry, and to corroborate the specifics of software licensing, software
development, publication embargoes and related issues linked to FWI at
Imperial College.

[10] Head of Global Technology at Hess to confirm the successful
application of the industrial-grade code to their major assets.

[11] Head of Geophysics for BG Group to confirm BG plan to purchase the
largest high-performance computer in South America specifically to run the
FWI software that Mike Warner's research team have developed